JP4363030B2 - Sound absorption structure for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sound absorbing structure for a vehicle, and more particularly, to a sound absorbing structure for a vehicle suitable for absorbing sound generated in an engine room such as an engine, sound generated in a vehicle compartment, and the like.
[0002]
[Prior art]
Conventionally, a sound absorbing structure that absorbs sound generated in an engine room of a vehicle is known (see, for example, Patent Document 1). In this sound absorbing structure, the upper part of the dash front as a soundproof material that covers the dash panel in the engine room is attached so as to rise obliquely toward the insulator hood that covers the hood panel. In this case, since a sound insulation space that covers the corner portion is formed between the upper portion of the dash front and the dash panel, the sound pressure at the corner portion of the engine room is reduced. In addition, a protrusion that contacts the upper edge of the dash front is formed at one end of the insulator hood. Since this protrusion always contacts the upper edge of the dash front upper, the sound insulation is improved.
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 5-44710 [0004]
[Problems to be solved by the invention]
However, in the sound absorbing structure disclosed in Patent Document 1, it is necessary to form a sound insulation space by the dash front and the dash panel in order to maintain quietness in the vehicle interior. It is necessary to provide a separate space.
[0005]
The present invention has been made in view of the above points, and an object thereof is to provide a vehicle sound absorbing structure capable of effectively realizing sound absorption without providing a separate space for sound insulation. And
[0006]
[Means for Solving the Problems]
The above-described object is, as described in claim 1, an engine cover formed in a mountain shape so that the front part is inclined downward in the front of the vehicle and the rear part is inclined downward in the rear of the vehicle;
A space portion formed to gradually decrease toward the center portion from the rear and toward the center portion in cross-sectional area from the front by said engine cover and an engine hood panel with the vehicle,
A sound absorbing material provided in the space;
It is achieved by Bei obtain sound absorbing structure for a vehicle.
[0007]
In this invention, the space part is formed so that a cross-sectional area may become small with the structure which a vehicle has. In this case, sound tends to concentrate in the space from the side with the larger cross-sectional area toward the side with the smaller cross-sectional area. In the present invention, a sound absorbing material is provided in the space. For this reason, the sound generated on the side of the space having a larger cross-sectional area , specifically, the sound generated in the engine room and transmitted to the upper side of the engine room is effectively absorbed.
[0008]
Incidentally, as described in claim 2, in the vehicle sound absorbing structure according to claim 1, wherein the space portion, if made of two spaces cross section an acute angle with the error down gin hood panel and the engine cover, Sound is more easily concentrated in the space, so that sound is effectively absorbed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side sectional view of a vehicle 12 including a vehicle sound absorbing structure (hereinafter simply referred to as a sound absorbing structure) 10 according to a first embodiment of the present invention. The vehicle 12 includes an engine room 16 in which an engine 14 that is vehicle power is disposed. The engine room 16 and the vehicle compartment 18 on which the vehicle occupant is boarded are separated by a dash panel 20. The dash panel 20 is a substantially plate-like member having sound insulation properties, and is vertically attached to the vehicle body side so that the normal line thereof faces the vehicle longitudinal direction. The dash panel 20 is formed such that a lower portion thereof is inclined toward the passenger compartment 18 side. The dash panel 20 mainly has a function of making it difficult for sound generated by the engine 14 in the engine room 16 to be transmitted to the passenger compartment 18.
[0013]
Below the engine 14, an engine under cover 22 constituting the lower part of the engine room 16 is disposed. The engine under cover 22 is a plate-like member having ventilation holes, and is horizontally attached to the vehicle body side so that the normal line thereof faces the vertical direction. The engine under cover 22 is connected to the lower part of the dash panel 20. That is, a space 24 is formed between the engine under cover 22 and the lower portion of the dash panel 20 so that the cross section when viewed from the side of the vehicle has an acute angle. The engine undercover 22 reduces the sound emitted from the engine room 16 to the outside of the vehicle together with the function of preventing the engine 14 from coming into direct contact with the protrusions on the road without disturbing the heat dissipation performance of the engine room 16. It has a function.
[0014]
An engine hood panel 26 that constitutes the upper portion of the engine room 16 is disposed above the engine 14. A predetermined gap is formed between the engine 14 and the engine hood panel 26. The engine hood panel 26 is a plate-like member composed of a hood outer panel and a hood inner panel, and is attached to the vehicle body side so that it can be opened and closed substantially horizontally or its front part slightly falls compared to the rear part. The engine hood panel 26 is connected to the upper part of the dash panel 20 via a seal 28. The engine hood panel 26 has a function of protecting the engine 14 and other components in the engine room 16.
[0015]
An instrument panel 30 in which operations and instruments are arranged is provided in the passenger compartment 18. Between the upper surface of the instrument panel 30 and the windshield glass 32 at the front of the vehicle body, a space 34 having a sharp cross section when viewed from the side of the vehicle is formed. A front defroster that mainly removes fogging of the windshield glass 32 at the front of the vehicle body is attached to the upper portion of the instrument panel 30.
[0016]
By the way, in order to ensure the quietness in the compartment 18, it is necessary to prevent the sound generated by the engine 14 and the like generated in the engine compartment 16 from being transmitted into the compartment 18. In this respect, since the dash panel 20 is formed between the engine room 16 and the vehicle compartment 18 as described above, it is possible to make it difficult for sound in the engine room 16 to be transmitted into the vehicle compartment 18.
[0017]
However, since the lower part of the dash panel 20 is formed so as to incline toward the passenger compartment 18 as described above, that is, in the vehicle width direction of the space 24 between the lower part of the dash panel 20 and the engine under cover 22. Since the cross-sectional area when cut by a vertical plane parallel to the vehicle gradually decreases from the front to the rear of the vehicle, the direct sound from the engine 14 and the reflection reflected by the dash panel 20 and the engine undercover 22 in the space 24 Sound is easy to concentrate. For this reason, the level of the sound transmitted from the part to the vehicle interior 18 is larger than the level of the sound transmitted from the other part to the vehicle interior 18. Therefore, in order to improve the quietness in the vehicle interior 18, It is effective to block and absorb the sound that propagates toward the passenger compartment 18 through the space 24 of the room 16.
[0018]
Therefore, the sound absorbing structure 10 of this embodiment is characterized in that it effectively blocks and absorbs the sound that propagates toward the vehicle compartment 18 via the space 24 of the engine room 16. Hereinafter, the characteristic part of a present Example is demonstrated.
[0019]
FIG. 2 shows an enlarged cross-sectional view of the sound absorbing structure 10 in the vehicle 12 shown in FIG. In the present embodiment, the space 24 between the lower portion of the dash panel 20 and the engine under cover 22 is provided with a sound absorbing material 40 at the entire corner so as to cover the corner as shown in FIG. The sound absorbing material 40 is disposed in a part of the space 24 extending in the vehicle width direction or preferably in the entire vehicle width direction. The sound absorbing material 40 is attached and fixed to the dash panel 20 or the engine under cover 22. The sound absorbing material 40 is made of a material such as glass wool or felt, and has a function of weakening an incoming sound wave by the action of its viscosity and heat conduction.
[0020]
In such a configuration, the sound absorbing material 40 absorbs sound collected in the space 24 between the dash panel 20 and the engine undercover 22. Since the space 24 is a part where the sound in the engine room 16 is likely to concentrate, the sound absorbing structure 10 can effectively absorb the sound generated in the engine room 16. For this reason, even when the engine 14 is in an operating state, the generated sound is hardly transmitted from the engine room 16 toward the vehicle interior 18 or toward the outside, and the quietness in the vehicle interior 18 can be reliably ensured. As well as being possible, it is possible to reduce the sound emitted to the outside of the vehicle.
[0021]
In the present embodiment, the sound absorbing material 40 is provided in a portion where the sound in the engine room 16 is likely to concentrate in order to ensure the quietness in the vehicle interior 18 and reduce the sound emitted to the outside of the vehicle. Therefore, it is not necessary to separately provide a sound insulation space such as a panel or a cover. Therefore, in the sound absorbing structure 10 of the present embodiment, the sound in the engine room 16 is effectively absorbed without providing a separate space for sound insulation, and the quietness in the passenger compartment 18 is ensured and the outside of the vehicle is secured. It is possible to reduce the sound emitted to the.
[0022]
In the first embodiment, the dash panel 20 and the engine under cover 22 are in the “structure” described in the claims, and the space 24 is in the “space” described in the claims. It corresponds.
[0023]
By the way, in the first embodiment described above, the sound absorbing material 40 is formed so as to cover the corner of the space 24 partitioned by the dash panel 20 and the engine under cover 22, and the sound absorbing material 40 is disposed on the entire corner. However, the present invention is not limited to this, and the sound absorbing material may be formed in a flat shape, and the sound absorbing material may be provided in a part of the space 24.
[0024]
That is, FIG. 3 shows an enlarged cross-sectional view of the sound absorbing structure 10 of this modification. In this modification, the space 24 has a sound absorbing material 50 attached to the surface of the lower end portion of the dash panel 20 and a sound absorbing material attached to the surface of the rear end portion of the engine undercover 22 as shown in FIG. 52 is provided. Similarly to the sound absorbing material 40, the sound absorbing materials 50 and 52 are made of a material such as glass wool or felt, and have a function of weakening the entering sound wave by the action of its viscosity and heat conduction. In such a configuration, the sound absorbing materials 50 and 52 effectively absorb sound collected in the space 24. Therefore, even in the sound absorbing structure 10 shown in FIG. 3, it is difficult for engine-generated sound to penetrate from the engine room 16 toward the vehicle compartment 18 or toward the outside, and it is possible to reliably ensure the quietness in the vehicle compartment 18. In addition, it is possible to reduce the sound emitted to the outside of the vehicle.
[0025]
Next, a second embodiment of the present invention will be described with reference to FIG. 4 together with FIG.
[0026]
In the first embodiment described above, the sound absorbing structure 10 absorbs sound transmitted from the engine room 16 to the vehicle compartment 18 and sound emitted from the engine room 16 through the engine under cover 22 to the outside of the vehicle. . On the other hand, the sound absorbing structure 100 of the present embodiment absorbs sound emitted from the engine room 16 through the engine hood panel 26 to the outside of the vehicle.
[0027]
FIG. 4 shows an enlarged cross-sectional view of the sound absorbing structure 100 of this embodiment in the vehicle 12 shown in FIG. In FIG. 4, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 4, an engine cover 102 is disposed in the gap between the engine 14 and the engine hood panel 26. The engine cover 102 has an engine hood whose front portion is inclined toward the front of the vehicle and whose rear portion is inclined toward the rear of the vehicle, that is, the cross section when viewed from the side of the vehicle extends from the front to the rear of the vehicle. It is formed in a mountain shape toward the panel 26. The engine cover 102 is attached to the engine 14 so as to cover the engine 14 from above. The engine cover 102 has a function of directly absorbing sound generated by the engine 14 and enhancing the design of the engine 14.
[0028]
Between the engine cover 102 and the engine hood panel 26, two spaces 104 and 106 having a sharp cross section when viewed from the side of the vehicle are formed. In such a configuration, the cross-sectional area of the spaces 104 and 106 partitioned by the engine cover 102 and the engine hood panel 26 when cut along a vertical plane parallel to the vehicle width direction extends from the front to the center, and thereafter Since the sound gradually decreases from the center to the center, the sound traveling from the front to the rear of the engine room 16 and the sound traveling from the rear to the front of the engine room 16 tend to concentrate in the spaces 104 and 106. .
[0029]
A hood insulator 108 is attached to the entire surface of the engine hood panel 26 on the engine room 16 side. The hood insulator 108 has a function of absorbing sound from the engine room 16, suppressing vibration of the engine hood panel 26, and blocking heat of the engine room 16.
[0030]
A flat sound absorbing material 110 is attached to the engine cover 102 so as to cover the surface of the engine hood panel 26 side. The sound absorbing material 110 abuts on the hood insulator 108 near the top of the engine cover 102 when the engine hood panel 26 is closed. The sound absorbing material 110 is disposed in a part of the spaces 104, 106 extending in the vehicle width direction or preferably in the entire vehicle width direction. The sound absorbing material 110 is made of a material such as glass wool or felt, like the sound absorbing material 40 of the first embodiment, and has a function of weakening the incoming sound wave by the action of its viscosity and heat conduction.
[0031]
In such a configuration, the sound absorbing material 110 attached to the engine cover 102 and the hood insulator 108 attached to the engine hood panel 26 generate sounds gathered in the spaces 104 and 106 between the engine hood panel 26 and the engine cover 102. Absorb. Since the spaces 104 and 106 are portions where the sound in the engine room 16 is likely to concentrate, the sound absorbing structure 100 can effectively absorb the sound generated in the engine room 16. For this reason, even when the engine 14 is in an operating state, the generated sound is difficult to be transmitted from the engine room 16 to the outside through the engine hood panel 26, and it is possible to reduce the sound emitted to the outside of the vehicle. In addition, it is possible to reliably ensure the quietness in the passenger compartment 18.
[0032]
In this embodiment, the engine cover that directly absorbs the sound generated by the engine 14 and enhances the design of the engine 14 in order to reduce the sound emitted to the outside of the vehicle and ensure the quietness in the passenger compartment 18. The cross-sectional area of the space 104, 106 formed by the engine cover 102 and the engine hood panel 26 at a vertical plane parallel to the vehicle width direction extends from the front to the center, and from the rear to the center. The sound generation material 110 and the hood insulator 108 may be provided in the spaces 104 and 106, so that the sound generated in the engine room 16 is easily concentrated. It is not necessary to provide a separate sound insulation space by a cover or a cover. Therefore, in the sound absorbing structure 100 of the present embodiment, the sound in the engine room 16 is effectively absorbed without providing a separate space for sound insulation, the sound emitted to the outside of the vehicle is reduced, and the vehicle interior 18 is also reduced. It is possible to ensure the quietness inside.
[0033]
In the second embodiment, the engine hood panel 26 and the engine cover 102 are provided in the “structure” described in the claims, and the spaces 104 and 106 are provided in the “space portion” described in the claims. , Respectively.
[0034]
By the way, in the second embodiment, when the engine cover 102 is viewed from the side of the vehicle such that the front portion thereof is inclined toward the front of the vehicle and the rear portion thereof is inclined toward the rear of the vehicle. However, the present invention is not limited to this and is inclined only toward the front of the vehicle. Alternatively, it may be formed so as to be inclined only toward the rear of the vehicle, or may be formed so as to be inclined toward the side of the vehicle.
[0035]
Further, in the second embodiment, the sound absorbing material 110 is formed in a flat shape so as to cover the surface of the engine cover 102 as shown in FIG. 4, and the sound absorbing material 110 is provided in a part of the spaces 104 and 106. However, the present invention is not limited to this, and the sound absorbing material is formed so as to cover the corners of the spaces 104 and 106 as in the sound absorbing material 40 of the first embodiment, and the entire corners are formed. It is good also as providing a sound-absorbing material.
[0036]
Next, a third embodiment of the present invention will be described with reference to FIG. 5 together with FIG.
[0037]
In the first and second embodiments described above, the sound absorbing structures 10 and 100 absorb sound transmitted from the engine room 16 to the vehicle compartment 18 and sound emitted from the engine room 16 to the outside of the vehicle. On the other hand, the sound absorbing structure 200 of the present embodiment absorbs sound transmitted from the vehicle compartment 18 to the engine compartment 16 or the outside of the vehicle.
[0038]
FIG. 5 shows an enlarged cross-sectional view of the sound absorbing structure 200 of the present embodiment in the vehicle 12 shown in FIG. In FIG. 5, the same components as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof is omitted. In this embodiment, the space 34 formed between the upper surface of the instrument panel 30 and the windshield glass 32 at the front of the vehicle body has corners as shown in FIG. 5 as long as the function of the front defroster is not impaired. The sound absorbing material 202 is provided on the entire corner so as to cover the part. The sound absorbing material 202 is disposed in a part of the space 34 extending in the vehicle width direction or preferably in the entire vehicle width direction. The sound absorbing material 202 is attached and fixed to the instrument panel 30. The sound absorbing material 202 is made of a material such as glass wool or felt, like the sound absorbing material 40, and has a function of weakening the incoming sound wave by the action of its viscosity and heat conduction.
[0039]
In such a configuration, the sound absorbing material 202 absorbs sound collected in the space 34 between the windshield glass 32 and the instrument panel 30. Since this space 34 is a part where the sound in the passenger compartment 18 tends to concentrate, therefore, according to the sound absorbing structure 200, it is possible to effectively absorb human voices and speaker sounds generated in the passenger compartment 18. Can do. In this case, it is difficult for the sound in the passenger compartment 18 to be transmitted to the outside of the vehicle, and the emitted sound can be reduced.
[0040]
In this embodiment, in order to reduce the sound emitted from the vehicle interior 18 to the outside of the vehicle, the sound absorbing material 202 may be provided in a portion where the sound in the vehicle interior 18 tends to concentrate. It is not necessary to provide a separate sound insulation space such as a panel. Therefore, in the sound absorbing structure 200 of the present embodiment, it is possible to effectively absorb the sound in the passenger compartment 18 and reduce the sound emitted to the outside of the vehicle without providing a separate space for sound insulation. .
[0041]
In a space where the cross section has an acute angle, such as the space 34 formed by the windshield glass 32 and the instrument panel 30 described above, when sound is input, the energy of the sound tends to concentrate, but on the contrary, the sound is output. In such a case, there is a characteristic that sound is radiated efficiently like a speaker, which may be a problem. In this embodiment, the sound absorbing material 202 provided in the space 34 between the windshield glass 32 and the instrument panel 30 is transmitted through the space 34 from the outside of the vehicle into the vehicle compartment 18 or from the engine room 16 to the space 34. It is possible to absorb sound that has passed through the vehicle interior 18 through the vehicle. Therefore, according to the sound absorbing structure 200 of this embodiment, it is possible to improve the quietness in the passenger compartment 18.
[0042]
In addition, in said 3rd Example, the instrument panel 30 and the windshield glass 32 are in the "structure" described in the claim, The space 34 is in the "space part" described in the claim, The windshield glass 32 corresponds to “vehicle glass” recited in the claims.
[0043]
By the way, in the third embodiment, the sound absorbing material 202 is formed so as to cover the corner of the space 34 partitioned by the instrument panel 30 and the windshield glass 32, and the sound absorbing material 202 is entirely formed in the corner. However, the present invention is not limited to this, and the sound absorbing material is formed in a flat shape, and the sound absorbing material is provided on a part of the space 34, for example, on the surface of the instrument panel 30. Also good.
[0044]
Further, in the first to third embodiments described above, the generated sound is absorbed by providing the sound absorbing material in the spaces 24, 34, 104, 106 formed with acute angles when viewed from the side of the vehicle. However, the present invention is not limited to this, and the generated sound can be absorbed even if a sound absorbing material is provided in a space having an obtuse cross section.
[0045]
【The invention's effect】
As described above, according to the first and second aspects of the present invention, it is possible to effectively realize the absorption of the sound generated on the side having the larger sectional area of the space , that is, the sound generated in the engine room .
[Brief description of the drawings]
FIG. 1 is a side sectional view of a vehicle having a sound absorbing structure according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a sound absorbing structure in the vehicle shown in FIG.
FIG. 3 is an enlarged sectional view of a sound absorbing structure according to a modification of the present invention.
FIG. 4 is an enlarged sectional view of a sound absorbing structure according to a second embodiment of the present invention.
FIG. 5 is an enlarged sectional view of a sound absorbing structure according to a third embodiment of the present invention.
[Explanation of symbols]
10, 100, 200 Sound absorbing structure 16 Engine room 18 Car compartment 20 Dash panel 22 Engine under cover 24, 34, 104, 106 Space 26 Engine hood panel 30 Instrument panel 32 Windshield glass 40, 50, 52, 110, 202 Sound absorbing Material 102 Engine cover 108 Hood insulator

Claims (2)

An engine cover formed in a mountain shape so that the front portion is inclined downward toward the front of the vehicle and the rear portion is inclined downward toward the rear of the vehicle;
A space portion formed to gradually decrease toward the center portion from the rear and toward the center portion in cross-sectional area from the front by said engine cover and an engine hood panel with the vehicle,
A sound absorbing material provided in the space;
Vehicle sound absorption structure, characterized in that to obtain Bei a.   2. The sound absorbing structure for a vehicle according to claim 1, wherein the space portion includes two spaces having an acute angle section by an engine hood panel and an engine cover.

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